A205459 Number of (n+1) X 2 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor.

256, 2120, 17920, 151824, 1285076, 10876432, 92062852, 779221408, 6595612052, 55825506424, 472525827000, 3999488656608, 33852918814560, 286533994691184, 2425307371380272, 20528052539179312, 173755089791996132

Offset

1,1

Comments

Column 1 of A205466.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 63*a(n-2) +50*a(n-3) +190*a(n-4) +42*a(n-5) +57*a(n-6) +122*a(n-7) +39*a(n-8) -12*a(n-9) for n > 10.

Example

Some solutions for n=4
..3..1....2..0....2..0....1..0....1..2....1..1....1..3....1..3....3..1....2..2
..1..3....2..3....1..2....0..1....0..1....2..0....3..3....1..3....1..1....1..0
..2..2....3..0....1..1....0..0....0..0....2..1....2..0....3..1....3..2....0..0
..1..3....2..1....0..2....3..2....0..0....1..1....0..0....1..1....3..0....0..0
..1..2....2..3....1..1....1..1....3..0....3..2....2..1....0..2....1..1....1..1

Crossrefs

Cf. A205466.

Sequence in context: A236445 A205954 A205466 * A237076 A237069 A346961

Adjacent sequences: A205456 A205457 A205458 * A205460 A205461 A205462

Keyword

nonn

Author

R. H. Hardin Jan 27 2012

Status

approved